Although technically, white rhinos are not extinct, things aren't looking good for the species. There are only two females left on the planet which means no natural opportunity for mating to occur. However, scientists were able to harvest sperm from Sudan, the last male rhino that died in March of 2018.
This means that specialists are in the process of attempting in vitro fertilization by removing eggs from both females in hopes for a successful pregnancy. Unfortunately, it seems as though the technology came about too late and it may not be functional. In short, humans didn't prevent poaching or care enough to take care of the species until it was too late.